import { BoundingSphere } from "../../Source/Cesium.js";
import { Cartesian3 } from "../../Source/Cesium.js";
import { mergeSort } from "../../Source/Cesium.js";

describe("Core/mergeSort", function () {
  it("sorts", function () {
    var array = [0, 9, 1, 8, 2, 7, 3, 6, 4, 5];
    mergeSort(array, function (a, b) {
      return a - b;
    });
    var expected = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
    expect(array).toEqual(expected);
  });

  it("stable sorts", function () {
    var array = [{ value: 5 }, { value: 10 }, { value: 5 }, { value: 0 }];
    var expected = [array[3], array[0], array[2], array[1]];
    mergeSort(array, function (a, b) {
      return a.value - b.value;
    });
    expect(array).toEqual(expected);
  });

  it("sorts with user defined object", function () {
    var array = [
      new BoundingSphere(new Cartesian3(-2.0, 0.0, 0.0), 1.0),
      new BoundingSphere(new Cartesian3(-1.0, 0.0, 0.0), 1.0),
      new BoundingSphere(new Cartesian3(-3.0, 0.0, 0.0), 1.0),
    ];
    var position = Cartesian3.ZERO;
    var comparator = function (a, b, position) {
      return (
        BoundingSphere.distanceSquaredTo(b, position) -
        BoundingSphere.distanceSquaredTo(a, position)
      );
    };
    var expected = [array[2], array[0], array[1]];
    mergeSort(array, comparator, position);
    expect(array).toEqual(expected);
  });

  function dummy() {
    return true;
  }

  it("throws an exception if array is missing", function () {
    expect(function () {
      mergeSort(undefined, dummy);
    }).toThrowDeveloperError();
  });

  it("throws an exception if comparator is missing", function () {
    expect(function () {
      mergeSort([0, 1, 2], undefined);
    }).toThrowDeveloperError();
  });
});